Rear sight for guns



March l5, 1927.

5. G. GREEN REAR SIGHT FOR GUNS Filed June l5, 1925 mm hm vm vf nuenfozE- E Green ammi Patented Mar. 15, 1927.

UNITED STATES SAMUEL G. GREEN,

OF GRAY, GEORGIA.

REAR SIGHT FOR GUNS.

Application filed .Tune 15, 1925.

(GRANTED UNDER THE ACT 0F The invention described herein may be used bythe Government, or any of its oiiicers or employees in prosecution ofwork for the Government, or by any other person in the United States,without payment to me of any royalty thereon, in accordance with the actof March 3, 1883.

This invention relates to a rear sight for guns and is especiallyadapted for use with machine guns.

The problem of aiming a gunat a ground target is entirely different fromthat of aiming the gun at an aerial target. The latter involvesadditional considerations due to the speed of an aeroplane and itsability to maneuver in an unrestricted eld. A sighting system which isprimarily designed for one class of targets can not, as a rule, be usedwith any degree of accuracy `against the other class.

The principal object of the present invention is to provide acombination rear sight for a sighting system which in addition to beingsimpler in constructional details than the customary single purposesight contains elements for sighting both ground and aerial targets. Therespective sightingapertures are provided at each end of a drift slidewhich is connected in a novel and simple manner to a main slide whichembraces the sight leaf in the customary manner. Provision is madeadjacent the lower peep sight aperture to afford the gunner theadvantage of a large field in picking up a target.

A further object of the invention is lto provide an index plate forreading the range elevations which may be adjusted to proper positionafter proof firing the gun.

The improvements are all incorporated in the slide units so that theymay be readily mounted on sight leafs now in use, replacing the singlepurpose sight.

To these and other ends, the invention consists in the construction,arrangement, and combination of elements, described hereinafter andpointed out in the claims forming a part of this specification.

A practical embodiment of my invention is illustrated in theaccompanying drawings, wherein:

1 is a View in rear elevation of a sight constructed in accordance withthe invention and showing the leaf in raised position;

Fig. 2 is a longitudinal section on the line 2-2 of Fig. l;

Serial No. 37,352.

MARCH 3, 1883; 22' STAT. L. 625.)

Fig. 3 is a cross section on the line 3-3 of "F ig. l;

Fig. LlA is a detail View of the drift slidc:

Fig. 5 is a detail view of the bate plate of the main slide; i

Fig. 6 is a detail view of the adjusting plate;

Fig. 7 is an end view of the adjusting plate;

Fig. 8 is a detail view of the main slide cap plate; and

Fig. 9 is a detail view of the half nut.

Referring to the drawings by numerals of reference:

There is shown a base G adapted to be mounted on a support (not shown)fixed to a gun and on thc base is pivoted a slotted sight leaf 7graduated in values of range. The leaf is of conventional design beingformed with an inclined guideway 8 and mounting a micrometer elevatingscrew 9.

The sliding units of the sight consist of a drift slide 10 disposed inthe inclined guideway 8 and a main slide 11 to which it is connected formovement and which embraces the leaf and is constrained thereby tovertical movement.

The main slide is preferably made up of two units, one being a baseplate 12 grooved asV at 13 to receive the leaf and have a sliding fitthereon, and the other being a cap plate 14 which may be secured to thebase plate by screws 15. The base plate includes a lug 16 disposed inthe slot of the leaf when the main slide is assembled and this lughouses a spring 17 which acts to normally hold a half nut 18 inengagement with the elevating screw 9. The half nut is carried in arecess 19 in the base plate and is formed with an angled portion 20adapted to engage the side of the leaf to limit its movement whenpressed inwardly by means of a thumb nut 2l pinned to its outerextremity.

The drift slide 10 is provided with two sighting apertures, the upperaperture 22 being used in aiming at aerial targets and the lower peepsight aperture 23 used for ground targets. Above the peep sight 23 is anarcuate aperture 24 which is provided as an orienting sight for thepurpose of afa fording a large field of view to enable the gunner toreadily pick up the target. This arrangement affords a peep sight havingall the advantages of an open sight without its disadvantages since theeye is not cognizant of the opening 24 when moved to focus through thepeep sight 23,.

In order that the drift slide may be moved in its inclined guidewaythrough the instrumentality of the main slide which is constrained tovertical movement it is provided, front and rear, with lugs 25 and 26respectively bearing against the upper side of the cap plate 14 and theunder side of the lug 16 on the base plate l2.

Due to variations in fabrication, the accuracy of the adjustment of thesights must' be verified by proof firing the gun or other-l wise testingit to establish a correct index o'r Zero. `Inasmuch as the range scaleinscribed on the sight leaf is fixed it is proposed to provide a movableindex plate for reading the ranges. The index plate 27 is thereforeformed with slots 28 whereby it may be adjustably secured to the capplate by` screws 29. n The plate is formed with a pair of pointers 30for reading the ranges on both sides of the leaf. It is further recessedas at 3l to permit its movement without interference with a battle sightlet on the cap plate 14.

The sighting aperture 22 is in the present instance dimensioned to beset at a range of two thousand (2,000) when aiming at aerial targets,this setting being dependent on the type of front sight employed inconjunction therewith.

I claim:

1. A rear sight for guns embodying a slotted leaf having an inclinedguideway, an elevating screw journaled in the leaf, a drift slidedisposed in the guideway and formed at its upper end with an aperturefor sighting aerial targets and at its lower end with an aperture forsighting ground targets, said slide further formed with an arcuateopening above the lower sighting aperture for the purpose ofestablishing a field of view, a main slide embracing the leaf andincluding a base plate grooved to receive the leaf, and a cap platesecured thereto, a battle sight carried by the cap plate, a half nutcarried by the base plate "and movable into and out of engagement withthe elevating screw, lugs on the front and rear of the drift slide andoppositely bearing against the cap plate and the base platt.,respectively, and an index plate adjustably secured to the cap plate andrecessed to receive the batt-le sight.

2. A rear sight for guns embodying a slotted leaf having an inclinedguidewaj, an elevating screw journaled in the leaf, a drift slidedisposed in the guideway and formed at its upper end with an aperturefor sighting aerial targets and at its lower end with an aperture forsighting ground targets, a

main slide embracing the leaf and including a base plate grooved toreceive the leaf and a cap plate secured thereto, a half nut carried bythe base plate and movable into and out of engagement with the elevatingscrew,

lugs on the front and rear of the drift slide.

for oppositely bearing against the cap plate andthe base platerespectively, and an index plate adjustably secured to the cap plate.

3. A rear sight for guns embodying a slotted leaf having an inclinedguideway, an elevating screw journaled in the leaf, a drift slidedisposed in the guideway and formed at its upper end with an aperturefor sighting aerial targets and at its lower end with a peep sight forsighting ground targets, a main slide embiacing` the leaf. lugs on thefront and rear of the drift slide for Oppositely bearing against theupper and lower sides of the main slide respectively, a battlc sight onthe main slide, a half nut carried by the main slide and movable intoand out of engagement with the elevating screw,

and an index plat-e adjustably secured to the main slide and recessedtoreceive the battle sight.

l. A rear sight for guns embodying a slotted leaf having an inclinedguideway, an elevating screw journaled in the leaf, a drift slidedisposed in the guideway and formed at its upper end with an aperturefor sighting aerial targets and at its lower end with a peep sight forsighting ground targets, a main slide embracing the leaf, a connectionbetween the drift and main slides whereby they are movable in unison, ahalf nut carried by the main slide and movable into and an arcuateopening above and adjacent they peep sight having the sight opening as acenter to establish a field of view to assist in picking up a target.

6. A rear sight for guns embodying a slotted leaf having an inclinedguideway, a drift slide in the guideway provided with a sightingaperture, a main slide embracing the leaf and connected to the driftslide, a battle sight on the main slide, and an adjustable range indexplate attached to the main slide and recessed to accommodate the battlesight.

7. A rear sight for guns embodying a slotted leaf having an inclinedguideway. a drift slide in the guideway provided with a sighting'aperture, a main slide embracing the leaf and connected to thedriftslide, and an vadjustable range index plate attached to the mainslide.

SAMUEL G. GREEN.

